KVM: x86: cleanup the code of read/write emulation

Using the read/write operation to remove the same code
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/x86/kvm/x86.c

@@ -4045,85 +4045,6 @@ static int vcpu_mmio_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva,
 	return 0;
 }
 
-static int emulator_read_emulated_onepage(unsigned long addr,
-					  void *val,
-					  unsigned int bytes,
-					  struct x86_exception *exception,
-					  struct kvm_vcpu *vcpu)
-{
-	gpa_t gpa;
-	int handled, ret;
-
-	if (vcpu->mmio_read_completed) {
-		memcpy(val, vcpu->mmio_data, bytes);
-		trace_kvm_mmio(KVM_TRACE_MMIO_READ, bytes,
-			       vcpu->mmio_phys_addr, *(u64 *)val);
-		vcpu->mmio_read_completed = 0;
-		return X86EMUL_CONTINUE;
-	}
-
-	ret = vcpu_mmio_gva_to_gpa(vcpu, addr, &gpa, exception, false);
-
-	if (ret < 0)
-		return X86EMUL_PROPAGATE_FAULT;
-
-	if (ret)
-		goto mmio;
-
-	if (!kvm_read_guest(vcpu->kvm, gpa, val, bytes))
-		return X86EMUL_CONTINUE;
-
-mmio:
-	/*
-	 * Is this MMIO handled locally?
-	 */
-	handled = vcpu_mmio_read(vcpu, gpa, bytes, val);
-
-	if (handled == bytes)
-		return X86EMUL_CONTINUE;
-
-	gpa += handled;
-	bytes -= handled;
-	val += handled;
-
-	trace_kvm_mmio(KVM_TRACE_MMIO_READ_UNSATISFIED, bytes, gpa, 0);
-
-	vcpu->mmio_needed = 1;
-	vcpu->run->exit_reason = KVM_EXIT_MMIO;
-	vcpu->run->mmio.phys_addr = vcpu->mmio_phys_addr = gpa;
-	vcpu->mmio_size = bytes;
-	vcpu->run->mmio.len = min(vcpu->mmio_size, 8);
-	vcpu->run->mmio.is_write = vcpu->mmio_is_write = 0;
-	vcpu->mmio_index = 0;
-
-	return X86EMUL_IO_NEEDED;
-}
-
-static int emulator_read_emulated(struct x86_emulate_ctxt *ctxt,
-				  unsigned long addr,
-				  void *val,
-				  unsigned int bytes,
-				  struct x86_exception *exception)
-{
-	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
-
-	/* Crossing a page boundary? */
-	if (((addr + bytes - 1) ^ addr) & PAGE_MASK) {
-		int rc, now;
-
-		now = -addr & ~PAGE_MASK;
-		rc = emulator_read_emulated_onepage(addr, val, now, exception,
-							vcpu);
-		if (rc != X86EMUL_CONTINUE)
-			return rc;
-		addr += now;
-		val += now;
-		bytes -= now;
-	}
-	return emulator_read_emulated_onepage(addr, val, bytes, exception,
-						vcpu);
-}
-
 int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
 			const void *val, int bytes)
 {
@@ -4208,16 +4129,21 @@ static struct read_write_emulator_ops write_emultor = {
 	.write = true,
 };
 
-static int emulator_write_emulated_onepage(unsigned long addr,
-					   const void *val,
+static int emulator_read_write_onepage(unsigned long addr, void *val,
 				       unsigned int bytes,
 				       struct x86_exception *exception,
-					   struct kvm_vcpu *vcpu)
+				       struct kvm_vcpu *vcpu,
+				       struct read_write_emulator_ops *ops)
 {
 	gpa_t gpa;
 	int handled, ret;
+	bool write = ops->write;
+
+	if (ops->read_write_prepare &&
+		  ops->read_write_prepare(vcpu, val, bytes))
+		return X86EMUL_CONTINUE;
 
-	ret = vcpu_mmio_gva_to_gpa(vcpu, addr, &gpa, exception, true);
+	ret = vcpu_mmio_gva_to_gpa(vcpu, addr, &gpa, exception, write);
 
 	if (ret < 0)
 		return X86EMUL_PROPAGATE_FAULT;
@@ -4226,15 +4152,14 @@ static int emulator_write_emulated_onepage(unsigned long addr,
 	if (ret)
 		goto mmio;
 
-	if (emulator_write_phys(vcpu, gpa, val, bytes))
+	if (ops->read_write_emulate(vcpu, gpa, val, bytes))
 		return X86EMUL_CONTINUE;
 
 mmio:
-	trace_kvm_mmio(KVM_TRACE_MMIO_WRITE, bytes, gpa, *(u64 *)val);
 	/*
 	 * Is this MMIO handled locally?
 	 */
-	handled = vcpu_mmio_write(vcpu, gpa, bytes, val);
+	handled = ops->read_write_mmio(vcpu, gpa, bytes, val);
 	if (handled == bytes)
 		return X86EMUL_CONTINUE;
 
@@ -4243,23 +4168,20 @@ static int emulator_write_emulated_onepage(unsigned long addr,
 	val += handled;
 
 	vcpu->mmio_needed = 1;
-	memcpy(vcpu->mmio_data, val, bytes);
 	vcpu->run->exit_reason = KVM_EXIT_MMIO;
 	vcpu->run->mmio.phys_addr = vcpu->mmio_phys_addr = gpa;
 	vcpu->mmio_size = bytes;
 	vcpu->run->mmio.len = min(vcpu->mmio_size, 8);
-	vcpu->run->mmio.is_write = vcpu->mmio_is_write = 1;
-	memcpy(vcpu->run->mmio.data, vcpu->mmio_data, 8);
+	vcpu->run->mmio.is_write = vcpu->mmio_is_write = write;
 	vcpu->mmio_index = 0;
 
-	return X86EMUL_CONTINUE;
+	return ops->read_write_exit_mmio(vcpu, gpa, val, bytes);
 }
 
-int emulator_write_emulated(struct x86_emulate_ctxt *ctxt,
-			    unsigned long addr,
-			    const void *val,
-			    unsigned int bytes,
-			    struct x86_exception *exception)
+int emulator_read_write(struct x86_emulate_ctxt *ctxt, unsigned long addr,
+			void *val, unsigned int bytes,
+			struct x86_exception *exception,
+			struct read_write_emulator_ops *ops)
 {
 	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
 
@@ -4268,16 +4190,38 @@ int emulator_write_emulated(struct x86_emulate_ctxt *ctxt,
 		int rc, now;
 
 		now = -addr & ~PAGE_MASK;
-		rc = emulator_write_emulated_onepage(addr, val, now, exception,
-						     vcpu);
+		rc = emulator_read_write_onepage(addr, val, now, exception,
+						 vcpu, ops);
+
 		if (rc != X86EMUL_CONTINUE)
 			return rc;
 		addr += now;
 		val += now;
 		bytes -= now;
 	}
-	return emulator_write_emulated_onepage(addr, val, bytes, exception,
-					       vcpu);
+
+	return emulator_read_write_onepage(addr, val, bytes, exception,
+					   vcpu, ops);
+}
+
+static int emulator_read_emulated(struct x86_emulate_ctxt *ctxt,
+				  unsigned long addr,
+				  void *val,
+				  unsigned int bytes,
+				  struct x86_exception *exception)
+{
+	return emulator_read_write(ctxt, addr, val, bytes,
+				   exception, &read_emultor);
+}
+
+int emulator_write_emulated(struct x86_emulate_ctxt *ctxt,
+			    unsigned long addr,
+			    const void *val,
+			    unsigned int bytes,
+			    struct x86_exception *exception)
+{
+	return emulator_read_write(ctxt, addr, (void *)val, bytes,
+				   exception, &write_emultor);
 }
 
 #define CMPXCHG_TYPE(t, ptr, old, new) \